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231.
232.
Hardware security has become more and more important in current information security architecture. Recently collected reports have shown that there may have been considerable hardware attacks prepared for possible military usage from all over the world. Due to the intrinsic difference from software security, hardware security has some special features and challenges. In order to guarantee hardware security, academia has proposed the concept of trusted integrated circuits, which aims at a secure circulation of IC design, manufacture and chip using. This paper reviews the main problems of trusted integrated circuits, and concludes four key domains of the trusted IC, namely the trusted IC design, trusted manufacture, trusted IP protection, and trusted chip authentication. The main challenges in those domains are also analyzed based on the current known techniques. Finally, the main limitations of the current techniques and possible future trends are discussed. 相似文献
233.
Zucong Cai 《Nutrient Cycling in Agroecosystems》2002,63(2-3):267-274
Coupled nitrification and denitrification is considered as one of the main pathways of nitrogen losses in paddy soils. The effect of NO3
– on NH4
+ transformation was investigated by using the 15N technique. The paddy soils were collected from Wuxi (soil pH 5.84) and Yingtan (soil pH 5.02), China. The soils were added with either urea (18.57 mol urea-N enriched with 60 atom% 15N excess) plus 2.14 mol KNO3-N (natural abundance) per gram soil (U+NO3) or urea alone (U). The KNO3 was added 6 days after urea addition. The incubation was carried out under flooded condition in either air or N2 gas headspace at 25°C. The results showed that in air headspace, 15NH4
+ oxidization was so fast that about 10% and 8% of added 15N in the treatment U could be oxidized during the incubation period of 73 hours after KNO3 addition in Wuxi and Yingtan soil, respectively. The addition of KNO3 significantly inhibited 15NH4
+ oxidation (p<0.01) in air headspace, while it stimulated 15NH4
+ oxidation in N2 gas headspace, although the oxidation was depressed by the N2 gas headspace itself. Therefore, the accumulation of NO3
– would inhibit further nitrification of NH4
+ at micro-aerobic sites in paddy soils, especially in paddy soils with a low denitrification rate. On the other hand, NO3
– would lead to oxidation of NH4
+in anaerobic bulk soils. 相似文献
234.
稀土顺丁橡胶与丁苯橡胶(SBR)共混,可以改善SBR的耐低温性能。当稀土顺丁橡胶/SBR(质量比)这20/80时,-30℃的tanδ仅小于SBR,60℃的tanδ最小。其共混胶的应力-应变性能、湿滑指数、磨耗及生热性能均优于镍系顺丁橡胶/SBR共混体系。 相似文献
235.
For a more accurate simulation of the moisture sorption process in wood, the precise separation of surface emission and diffusion coefficients is essential. In this paper, a non-linear simplex technique that was developed to obtain the optimum pair of the surface emission coefficient he, and the diffusion coefficient D from a single sorption curve is presented and tested with experimental data. An easy to use computer program was employed to carry out the evaluation. Data analysis showed that the new method resulted in a more statistically accurate calculation of bc and D than currently existing methods. 相似文献
236.
237.
Are quantum dots ready for in vivo imaging in human subjects? 总被引:2,自引:0,他引:2
Nanotechnology has the potential to profoundly transform the nature of cancer diagnosis and cancer patient management in the
future. Over the past decade, quantum dots (QDs) have become one of the fastest growing areas of research in nanotechnology.
QDs are fluorescent semiconductor nanoparticles suitable for multiplexed in vitro and in vivo imaging. Numerous studies on
QDs have resulted in major advancements in QD surface modification, coating, biocompatibility, sensitivity, multiplexing,
targeting specificity, as well as important findings regarding toxicity and applicability. For in vitro applications, QDs
can be used in place of traditional organic fluorescent dyes in virtually any system, outperforming organic dyes in the majority
of cases. In vivo targeted tumor imaging with biocompatible QDs has recently become possible in mouse models. With new advances
in QD technology such as bioluminescence resonance energy transfer, synthesis of smaller size non-Cd based QDs, improved surface
coating and conjugation, and multifunctional probes for multimodality imaging, it is likely that human applications of QDs
will soon be possible in a clinical setting. 相似文献
238.
Methane oxidation in paddy soils was investigated under laboratory conditions. Paddy soils collected before early rice transplanting
could not oxidize atmospheric CH4 but could oxidize CH4 when the concentration exceeded 10 μl l-1. Initial CH4 oxidation rate increased with the increase of initial CH4 concentration. Soil with the maximum potential to produce CH4, also had the maximum CH4 oxidation activity and the maximum emission flux from paddy soil. High CH4 concentration stimulated the oxidation of CH4. After 10 days' incubation under atmosphere containing 1000 μl-1 or 104 μl l-1 CH4, the soil which could not oxidize atmospheric CH4 was able to oxidize it.
This revised version was published online in August 2006 with corrections to the Cover Date. 相似文献
239.
The copolymerization of carbazole (CZ) and 3‐methylthiophene (3MeT) was successfully performed electrochemically in freshly distilled boron trifluoride diethyl etherate by direct anodic oxidation of the monomer mixtures, although the oxidation potentials of CZ and 3MeT were quite different. The electrochemical properties of the copolymers were studied with cyclic voltammetry. The influence of the applied polymerization potential on the synthesis of the copolymers was investigated. The higher potential favored the incorporation of 3MeT units into the copolymers. The insertion of 3MeT units into polycarbazole (PCZ) was helpful in improving the conductivity of PCZ. The novel copolymers had the advantages of both PCZ and poly(3‐methylthiophene), that is, good redox activity, good thermal stability, and high conductivity. The structure and morphology of the copolymers were investigated with ultraviolet–visible, infrared spectroscopy, thermal analysis, and scanning electron microscopy. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 102: 1877–1885, 2006 相似文献
240.
针对企业电力负荷随机性强、稳定性低、预测精度不理想等问题,提出了一种基于最大偏差相似性准则的BP神经网络短期电力负荷预测算法。首先对最大偏差相似性准则算法进行修改,并提出使用预测日的负荷特征向量与最大偏差相似性准则算法聚类之后的类中心负荷特征的距离来确定预测日的相似日类别;然后将聚类后的相似日类别负荷数据作为BP网络的训练数据,输出预测日起始的连续三天96整点负荷值。实验表明,该方法提出的短期电力负荷预测方法在精度和网络训练时间上都有较大的提升,具有较高的有效性和实用性。 相似文献